本文選題：無線射頻識(shí)別技術(shù) + 超高頻近場系統(tǒng)��； 參考：《杭州電子科技大學(xué)》2015年碩士論文

【摘要】：隨著互聯(lián)網(wǎng)和通信技術(shù)的日益成熟，物聯(lián)網(wǎng)（IoT）這個(gè)新興概念越來越多的被人所提及，而作為物聯(lián)網(wǎng)核心技術(shù)的無線射頻識(shí)別技術(shù)（RFID）也被廣泛的應(yīng)用于物流、制造、公共安全等領(lǐng)域中。一直以來，RFID技術(shù)的應(yīng)用方向分為超高頻的托盤級(jí)識(shí)別和高頻/低頻的物品級(jí)識(shí)別，在同一頻段同時(shí)實(shí)現(xiàn)托盤級(jí)識(shí)別和物品級(jí)識(shí)別一直備受關(guān)注，超高頻近場系統(tǒng)被認(rèn)為是解決這一難題的主要方案。 天線是RFID系統(tǒng)中的一個(gè)重要組成部分，直接影響著整個(gè)系統(tǒng)的工作性能。本項(xiàng)目的近場系統(tǒng)工作在天線的感應(yīng)場區(qū)，采用電感耦合的工作方式，以環(huán)天線理論和半波偶極子天線理論為基礎(chǔ)，分別對(duì)近場系統(tǒng)的標(biāo)簽天線和讀寫器天線展開研究： （1）通過分析超高頻近場標(biāo)簽天線電路模型，提出偶極子天線加載電小環(huán)天線的天線結(jié)構(gòu)。但由于尺寸的限制，單個(gè)偶極子臂有效長度不足以達(dá)到諧振頻率所對(duì)應(yīng)的四分之一波長，故無法保證天線工作頻率達(dá)到設(shè)計(jì)要求；而且近場標(biāo)簽要有較強(qiáng)的環(huán)境適應(yīng)能力需要有塊狀結(jié)構(gòu)形成大電容以增強(qiáng)儲(chǔ)存能量的能力。因此，提出一種特殊結(jié)構(gòu)電小環(huán)集成圓弧形偶極子臂的天線結(jié)構(gòu)，并用HFSS進(jìn)行建模仿真，優(yōu)化設(shè)計(jì)后得到最優(yōu)結(jié)構(gòu)和尺寸，最終仿真結(jié)果顯示天線中心頻率為910MHz，與芯片阻抗匹配，，電壓駐波比小于1.5。 （2）以讀寫器天線近場區(qū)域能夠產(chǎn)生均勻的電磁場分布為設(shè)計(jì)核心，提出反向電流對(duì)加載開口諧振環(huán)的天線結(jié)構(gòu)：用偶極子臂構(gòu)建反向電流對(duì)，用電小環(huán)天線構(gòu)建開口諧振環(huán)，并用HFSS進(jìn)行建模仿真，優(yōu)化設(shè)計(jì)后得到最優(yōu)結(jié)構(gòu)和尺寸，仿真結(jié)果顯示讀寫器近場區(qū)域內(nèi)電磁場分布均勻，且具有較強(qiáng)的電場強(qiáng)度和磁場強(qiáng)度，天線中心頻率為920MHz，與50歐姆實(shí)現(xiàn)阻抗匹配，電壓駐波比小于1.5。 最后，對(duì)該超高頻RFID近場系統(tǒng)測試，測試結(jié)果顯示該系統(tǒng)閱讀性能良好，可達(dá)6.5cm；系統(tǒng)具有較強(qiáng)的環(huán)境適應(yīng)性，貼附在各種材質(zhì)上的閱讀距離均可大5cm，但在金屬環(huán)境中使用時(shí)需離開金屬表面至少1cm。
[Abstract]:With the development of Internet of things and communication technology, the new concept of IoT has been more and more mentioned, and RFID, the core technology of Internet of things, has been widely used in logistics and manufacturing. In areas such as public safety The application of RFID technology has been divided into ultra-high frequency pallet level identification and high frequency / low frequency object level identification. UHF near-field system is considered to be the main solution to this problem. Antenna is an important part of RFID system, which directly affects the performance of the whole system. The near field system of this project works in the inductive field region of the antenna. Based on the theory of loop antenna and half wave dipole antenna, the label antenna and reader antenna of the near field system are studied by inductively coupled mode. 1) by analyzing the circuit model of UHF near-field tag antenna, the antenna structure of electric small loop antenna loaded with dipole antenna is proposed. However, due to the limitation of size, the effective length of a single dipole arm is not enough to reach the 1/4 wavelength corresponding to the resonant frequency, so it is impossible to guarantee the antenna working frequency to meet the design requirements. In addition, the near field tag needs to have a large capacitance to enhance the energy storage ability to have a large block structure to be able to adapt to the environment. Therefore, an antenna structure with a special structure, the electric small ring integrated circular arc dipole arm is proposed, and the optimal structure and size are obtained by HFSS modeling and simulation. The simulation results show that the center frequency of the antenna is 910MHz, which matches the chip impedance, and the VSWR is less than 1.5. Taking the near-field distribution of electromagnetic field in the near field of reader antenna as the design core, an antenna structure with reverse current pair loaded with open resonant ring is proposed: the reverse current pair is constructed by dipole arm, and the open resonant ring is constructed by electric small loop antenna. Using HFSS to model and simulate, the optimal structure and size are obtained after optimized design. The simulation results show that the electromagnetic field in the near field region of the reader is uniform, and has a strong electric and magnetic field intensity. The center frequency of the antenna is 920MHz, and the impedance is matched with 50 ohms. The VSWR is less than 1.5. Finally, the test results of the UHF RFID near-field system show that the reading performance of the system is good, which can reach 6.5 cm, and the system has strong environmental adaptability. The reading distance attached to various materials can be 5 cm, but when used in metal environment, it must be at least 1 cm off the metal surface.
【學(xué)位授予單位】：杭州電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TP391.44

【參考文獻(xiàn)】

相關(guān)期刊論文 前4條

1 尹寒,陳峰;近耦合射頻識(shí)別系統(tǒng)的工作原理及天線設(shè)計(jì)[J];單片機(jī)與嵌入式系統(tǒng)應(yīng)用;2002年01期

2 巨天強(qiáng);;RFID的發(fā)展及其應(yīng)用的現(xiàn)狀和未來[J];甘肅科技;2009年15期

3 蘇艷;黃海洋;陳東杰;;UHF頻段近場耦合RFID讀寫器天線設(shè)計(jì)[J];科學(xué)技術(shù)與工程;2011年19期

4 耿淑琴;侯立剛;郭躍;王秀玲;吳武臣;;基于MSP430控制的射頻識(shí)別讀寫器設(shè)計(jì)(英文)[J];吉首大學(xué)學(xué)報(bào)(自然科學(xué)版);2007年02期

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